Heater related fumes in cockpit

[Vixxen]

Recent 4-5 hour trip in my 3 year old A32 Aeroprakt Vixxen. About two hours into trip we noticed a strange smell in cabin. Not pungent or irritating but couldn't be cleared by venting the cabin. Had the heater on at that stage so turned it off as well as some electrics and it reduced. CO2 monitor didn't activate. Diverted to a nearby strip, pulled the cowl off and had a good look where we could. Did we imagine it? Took off and flew another 3-4 hours that day with no further issues but kept heater off. Next day flew home, tried heater again on low and had no issues. Any thoughts?

Edited 9 hours ago by Vixxen

[skippydiesel]

Bit scary to say the east. CO poisoning is insidious and cockpit heaters, that run of the exhaust silencer (or similar), are to be suspected at all times. Be very very cautious,, even a pin hole in the wrong place could shorten your life.😈

[Freizeitpilot]

CO by itself is odourless, but when mixed with exhaust gas you will smell that instead. Also be aware that CO poisoning is cumulative - a low concentration over a longer period can also be very dangerous.

What type of CO monitor - a sticker or something else ? Confirm its function if you can.

 

A 3 year old aircraft - have you regularly used the heater before ? If you’re lucky, it may be the volatiles coming out of the (plastic ?) ducting from the initial heat, if you’ve never used it before ??

 

As Skippy mentions - be incredibly cautious and investigate thoroughly.
 

[Thruster88]

The a32 vixxen heater works by ducting heated air from the main front mounted engine radiator. There would be almost zero chance of co2 or any engine bay smells entering this system. Perhaps an antifreeze smell if there was a coolant leak?

Edited 7 hours ago by Thruster88

[skippydiesel]

30 minutes ago, Thruster88 said:

The a32 vixxen heater works by ducting heated air from the main front mounted engine radiator. There would be almost zero chance of co2 or any engine bay smells entering this system. Perhaps an antifreeze smell if there was a coolant leak?

Thats interesting - I hadnt heard of a cabin heat system like the one you describe. From your descriptions it sounds like there is no chance of exhaust (CO) being drawn in to the heating system. Still I would be cautious - air flows in the engine compartment can be counterintuitive. 😈

[Vixxen]

7 hours ago, Freizeitpilot said:

CO by itself is odourless, but when mixed with exhaust gas you will smell that instead. Also be aware that CO poisoning is cumulative - a low concentration over a longer period can also be very dangerous.

What type of CO monitor - a sticker or something else ? Confirm its function if you can.

 

A 3 year old aircraft - have you regularly used the heater before ? If you’re lucky, it may be the volatiles coming out of the (plastic ?) ducting from the initial heat, if you’ve never used it before ??

 

As Skippy mentions - be incredibly cautious and investigate thoroughly.
 

I've a CO Gas Alarm as well as an inbuilt detector on our Lightspeed headsets. Neither of those alarmed. I've used the heater a handful of times before but probably not as long as this time, maybe an hour or more. The "volatiles" you mention could be the reason or maybe as someone else mentioned, maybe coolant/antifreeze though I could not see any evidence of a leak. Thanks for your reply. Cheers

Edited 17 minutes ago by Vixxen

[Vixxen]

7 hours ago, Thruster88 said:

The a32 vixxen heater works by ducting heated air from the main front mounted engine radiator. There would be almost zero chance of co2 or any engine bay smells entering this system. Perhaps an antifreeze smell if there was a coolant leak?

Thank you for this. The coolant leak could well have been the issue. I've just realised that during the DI before we took off, my wife had taken off the coolant cap (cold) and there was a tiny bit of pressure which led to some spillage. I thought we had cleaned it up but in all likelihood we missed some. Thinking back, the smell was likely coolant. Thanks everyone for your input.